Collaborative arrangements are being made with various manufacturers of x-ray sources and a variety of Government agencies to extend current efforts to develop and evaluate improved dental radiographic systems. Previous work was centered evaluation of a prototype system which coupled a modified rod anode source to a special polaroid cassette and conventional film-screen systems. (Project Number Z01 DE 00065-05 CI C) Findings derived from geometric models and analyses of source signal to noise power ratios as well as clinical studies suggest that extensions of this configuration can significantly reduce absorbed dose while preserving information of diagnostic interest. This approach is being extended to include consideration of isotopic sources, miniaturized image intensifiers, and rare earth filtered spectra. Prototype machines are being developed from these elements which will ultimately be analyzed via computer simulation studies and clinical evaluations.